Stated plainly: orforglipron · 4 °C · ten days.
I would like to set this up properly once, rather than adjust it repeatedly.
My budget is real but not tight, and my tolerance for uncertainty is low.
What would you do, and what would make you change course?
Ten days at 4 °C is about 9 refrigerated days of equivalent exposure. 4 °C is the condition the rule of thumb is anchored to, so it is the baseline rather than a multiplier: everything else in this thread is quoted relative to it. At 9 equivalent days a test is more likely to reassure you than to tell you something, which is a legitimate reason to run it and a poor reason to expect a finding. Either way, record the ten days and the temperature now, while you still know them; an excursion you did not write down is an excursion you cannot interpret later.
The part that matters: if temperature history matters to you, buy a data logger. It is the only way to know.
Anything shipped in solution is a different risk category, because hydrolysis and deamidation proceed in the aqueous phase and are strongly temperature-dependent.
A single phase-change pack in a thin-walled box holds below ten degrees for roughly one to two days at twenty-five degrees ambient, and under a day at thirty-five. On a nine-to-fourteen-day lane the material is at ambient for most of the journey whatever was packed with it.
Solid-state stability of lyophilised peptides at ambient temperature is documented in formulation studies with residual moisture as the dominant variable.
Nothing here is medical advice, and research-use compounds are not approved for human use.
Buy a logger if you actually want to know. Everything else is inference.
HPLC purity, identity confirmation and quantified content on the vial you actually hold. Reports arrive with the chromatogram attached, not just a number.
Submit a sampleFounded 1998. ISO 9001 and cGMP certified, 1,500+ staff and 200+ patents. The synthesis house behind a great many of the vials that get sent out for testing - batch-specific documentation with every order.
Visit GL BiochemAnswering this needs the transit duration and the ambient temperature, and then the arithmetic is straightforward.
That is the argument for shipping lyophilised rather than for shipping colder. A dry powder with low residual moisture is stable at ambient for months; the pathways that matter need water.
Once the parcel arrives, the domestic leg is the controllable part: get it into the refrigerator promptly rather than leaving it in a warm hallway for a day.
The domestic leg is the part you control. Refrigerate it promptly.
edited 10 Apr 2026 by Dr_Otto_Lindqvist — updated for the 2026 guidance change
To be exact about it, the domestic leg after arrival is the part most often left in a warm hallway and least often worried about.
Asking a supplier to hold a shipment during a heatwave is reasonable and the better ones agree; the cost is a week and the benefit is a shorter warm exposure for anything in solution.
Arrhenius behaviour means the degradation rate roughly doubles per ten degrees. A week at thirty degrees is therefore a meaningful exposure for a solution and an immaterial one for a dry solid.
Single-use temperature loggers are standard practice in supply chains where temperature genuinely matters and are inexpensive at parcel scale.
A liquefied pack is expected. It is not evidence of a problem.
Put another way, this is where the anxiety in this hobby is most out of proportion to the chemistry.
A single-use temperature logger costs a few pounds, records the whole journey and converts an argument into a record. If the history matters, this is the answer.
Solutions are a different question and deserve the worry the solids get.
Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.